JP2005291994A - System for monitoring water quality - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for monitoring water quality for automatically monitoring a plurality of samples which have different water qualities, using one measurment apparatus. <P>SOLUTION: For acquiring calibration data, the remaining nitrogen concentration of water in a hot spring bath 1a is measured by a sensor 12 by opening a solenoid value 11a, and an obtained measurement value X is stored at a measurement value storage section 16 for calibration as a measurement value Sa for calibration. The remaining nitrogen concentration of water passing through the sensor 12 is simultaneously inspected by a DPD method, and the obtained inspection value is accommodated at a concentration inspection value storage section 19 as a concentration inspection value Ka. The solenoid valve 11a is opened in normal monitoring, and the water in the hot spring bath 1a is measured by the sensor 12. Then, the obtained measurement value X is given to a nitrogen concentration calculation section 15 and is calibrated by the measurement value Sa for calibration and the concentration inspection value Ka, and thus a concentration value Y, corresponding to the inspection result by the DPD method, is calculated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water quality management system for monitoring the concentration of impurities such as residual chlorine contained in sewage treated water, factory effluent, pool water, and the like.

  Conventionally, water quality management of sewage treated water, factory effluent, pool water, etc. has been conducted by periodically collecting water for inspection (hereinafter referred to as test water) and measuring the residual chlorine as described in Patent Document 1 below. In this method, the residual chlorine concentration was measured, and the addition amount of the chlorine-based disinfectant was determined based on the measurement result, and the residual chlorine concentration was adjusted to be within the reference value.

JP 2000-275214 A

  However, the residual chlorine measuring device conventionally used in water quality management applies a DC measurement voltage between the electrodes arranged opposite to each other in the test water, and measures the oxidation-reduction current flowing between the electrodes, The residual chlorine concentration in the sample is measured. For this reason, when measuring water quality with different main components, such as sewage treated water or factory effluent, the electrical conductivity and hydrogen ion concentration differ depending on the difference in components other than the residual chlorine concentration, and the base current depends on the water to be measured. The values are different. For this reason, it is necessary to calibrate the residual chlorine measuring device for each measurement, which is a very laborious operation.

  In addition, when automating these operations, it is necessary to install an independent residual chlorine measuring device for each monitoring target in order to eliminate the need for calibration processing of the residual chlorine measuring device for each measurement. There was a problem of increasing.

  An object of the present invention is to provide a water quality management system which can automatically monitor a plurality of samples having different water qualities by sharing one measuring apparatus.

  The water quality monitoring system of the present invention includes a water intake means for switching and collecting a plurality of systems of water according to a selection signal, and a detection means for outputting an electrical signal corresponding to the concentration of a specific component contained in the water collected by the water intake means. A conversion means for converting the electrical signal output from the detection means into a digital value and outputting it as a measurement value; and at the time of acquiring calibration data for the water of the plurality of systems, the measurement value output from the conversion means for each system A first storage means for storing as a measurement value for calibration in the apparatus, and a concentration obtained by inspecting a concentration of a specific component contained in water collected by the water intake means at the time of obtaining the calibration data by an inspection method as an evaluation standard Second storage means for storing the inspection value for each system, and the measured value output from the conversion means for the water of each system collected by the water intake means during water quality monitoring, Calibration is performed using the corresponding calibration measurement value and the concentration test value, and the selection signal for the water intake means is output based on the concentration calculation means for calculating the corresponding concentration value and the operation plan data given in advance. And control means for controlling the entire operation sequence.

  In the present invention, at the time of calibration data acquisition, the calibration measurement value obtained by detecting the concentration of the specific component contained in the sampled water sampled for each of the plurality of systems by the detection unit and converting it by the conversion unit is stored. 1 storage means, and a second storage means for storing a concentration test value obtained by inspecting the concentration of a specific component contained in the same test water by an inspection method as an evaluation standard. Thereby, water for inspection is periodically collected by water quality monitoring, and the measurement value of the specific component of the collected water is calibrated using the calibration measurement value and the concentration inspection value stored as calibration data. Thus, it is possible to calculate a concentration value corresponding to the inspection method as an evaluation standard. Therefore, there is an effect that a plurality of samples having different water qualities can be automatically monitored by one measuring device.

  It is obtained by measuring the zero point adjustment value, which is a measurement value output from the conversion means when the test water is not collected, with a sensor and the concentration of a specific component contained in the water of the corresponding system at the time of calibration data acquisition. Sa is a measured value for calibration, and Ka is a concentration inspection value obtained by inspecting the concentration of a specific component contained in the same water by an inspection method as an evaluation standard. And the measured value of the test water sampled by the water quality monitoring performed periodically is set to X, and the concentration value Y of the test water is calculated using the formula of Y = Ka (X-Sz) / (Sa-Sz). .

  The above and other objects and novel features of the present invention will become more fully apparent when the following description of the preferred embodiment is read in conjunction with the accompanying drawings. However, the drawings are for explanation only, and do not limit the scope of the present invention.

FIG. 1 is a configuration diagram of a residual chlorine concentration monitoring system showing an embodiment of the present invention.
This residual chlorine concentration monitoring system monitors and controls the residual chlorine concentration contained in a plurality of systems of water having different water quality such as a hot spring bathtub 1a and a pool 1b.

  The water in the hot spring bathtub 1a is circulated by the circulation pump 2a, and a part of the water is sent from the flow rate adjustment valve 3a to the water intake means (for example, an electromagnetic valve) 11a through the water supply pipe 4a. Similarly, the water in the pool 1b is circulated by the circulation pump 2b, and a part of the water is sent from the flow rate adjustment valve 3b to the electromagnetic valve 11b through the water supply pipe 4b.

  Detection means (for example, a sensor) 12 for detecting the residual chlorine concentration is connected to the outlet side of the electromagnetic valves 11a and 11b, and the water sample selected and collected by these electromagnetic valves 11a and 11b is used as a sensor. 12 is discharged through.

  The sensor 12 arranges two electrodes facing each other in the flow path of the test water, applies a DC voltage between these electrodes, and detects a weak current flowing between the electrodes. A weak voltage corresponding to the weak current detected by the sensor 12 is amplified by a direct current amplifier, converted into a digital value by a conversion means (for example, ADC: analog-digital converter) 13, and output as a measured value X. It has become.

  A calibration data input unit 14 and a concentration calculation unit (for example, a chlorine concentration calculation unit) 15 are connected to the output side of the ADC 13. The calibration data input unit 14 reads the measurement value X output from the ADC 13 on the basis of a timing signal given from a control unit (for example, a sequence control unit) 20 described later at the time of obtaining calibration data, and uses it as a measurement value for calibration. The first storage means (for example, a calibration measurement value storage unit) 16 is stored.

  The chlorine concentration calculation unit 15 calibrates the measurement value X output from the ADC 13 according to the measurement value for calibration and the concentration inspection value based on the timing signal provided from the sequence control unit 20 during water quality monitoring, and the concentration of residual chlorine. The value Y is calculated. The concentration value Y calculated by the chlorine concentration calculation unit 15 is supplied to a concentration determination means (for example, a concentration determination unit) 17. The density determination unit 17 determines whether or not the density value Y is within the set management range. When the density value Y falls below the lower limit value, the lower limit detection signal LL is obtained. When the density value Y exceeds the upper limit value, the upper limit detection signal UL is obtained. Each is output to the sequence control unit 20.

  Further, in this residual chlorine concentration monitoring system, when the calibration data is acquired, the residual chlorine concentration of the test water discharged from the sensor 12 is inspected by the DPD method (diethyl-P-phenylenediamine colorimetric method) and obtained by the inspection. In addition, an inspection data input unit 18 is provided for manually inputting inspection values for the PDP method. The DPD method is an inspection method for residual chlorine concentration, which is an evaluation standard. Sample water is collected in a colorimetric cell for measurement, a DPD reagent is added thereto, and the degree of pink color development is compared with a color sample. This is a visual and manual inspection method for determining the residual chlorine concentration. The PDP method test value input from the test data input unit 18 by the operator is stored in the second storage means (for example, the density test value storage unit) 19 as a density test value.

  The sequence control unit 20 outputs a selection signal for opening and closing the electromagnetic valves 11a and 11b based on the operation plan data such as a daily operation schedule and a one-year calendar stored in the operation plan data storage unit 21. At the same time, the operation sequence of the calibration data input unit 14, the chlorine concentration calculation unit 15, and the concentration determination unit 17 is controlled. Furthermore, when the lower limit detection signal LL or the upper limit detection signal UL is output from the concentration determination unit 17, the sequence control unit 20 uses the chlorine injection pumps 5a and 5b provided in the hot spring bath 1a, the pool 1b, etc. to maintain the water quality. The amount of chlorine injected for sterilization is adjusted. The sequence control unit 20 is connected to an operation unit such as a touch panel 22 for outputting a warning or display to the operator and receiving control from the operator.

  Next, the operation and function of this residual chlorine concentration monitoring system will be described.

(1) Acquisition of calibration data for calculating the chlorine concentration First, in accordance with an operator instruction performed through the touch panel 22, calibration values are input to the measurement values X output from the ADC 13 with all the solenoid valves 11a and 11b closed. The data is taken in by the unit 14 and stored in the calibration measurement value storage unit 16 as the zero point adjustment value Sz.

  This is because current does not flow between the electrodes of the sensor 12 unless water is detected between the electrodes of the sensor 12, but it is obtained by the influence of the offset voltage of the DC amplifier for measuring this and the characteristics of the ADC 13. This is because the measured value X is not necessarily zero.

  Next, in order to obtain the measurement value for calibration of water in the hot spring bathtub 1a, a selection signal for opening the electromagnetic valve 11a is output from the sequence control unit 20. Thereby, the water of the hot spring bathtub 1a flows into the sensor 12, and the measured value X is output from the ADC 13. The measurement value X is captured by the calibration data input unit 14 and stored in the calibration measurement value storage unit 16 as the calibration measurement value Sa.

  On the other hand, the water discharged through the sensor 12 is collected, and the residual chlorine concentration is measured by manual analysis using the DPD method. The measured DPD method test value is manually input from the test data input unit 18 by the operator and stored in the density test value storage unit 19 as the density test value Ka.

  Similarly, the water in the pool 1b is measured by the sensor 12, and the measurement value X output from the ADC 13 is stored in the calibration measurement value storage unit 16 as the calibration measurement value Sb, and the same water sample is measured by the DPD method. The density test value Kb obtained in this manner is stored in the density test value storage unit 19.

  Through the above operation, calibration data (zero point adjustment value Sz, calibration measurement values Sa and Sb, and concentration test values Ka and Kb) for calculating the chlorine concentration of the hot spring bathtub 1a and pool 1b are obtained, and calibration measurement is performed. The values are stored in the value storage unit 16 and the density inspection value storage unit 19. This operation is systematically performed on all monitored water systems. For example, when the water temperature varies greatly depending on the season, such as treated sewage water, the distribution of components other than the residual chlorine concentration changes due to changes in the water temperature, so every relatively short period (for example, 2 weeks) Calibration data needs to be retaken.

(2) Residual chlorine concentration monitoring and control Next, in order to manage the water quality of the hot spring bathtub 1a and the pool 1b, the residual chlorine concentration is monitored periodically (for example, every hour). This is performed by the sequence control unit 20 according to the operation plan data stored in the operation plan data storage unit 21.

  First, a selection signal for opening the solenoid valve 11a is output from the sequence control unit 20. Thereby, the water of the hot spring bathtub 1a flows into the sensor 12, and the measured value X is output from the ADC 13. The measurement value X is given to the chlorine concentration calculation unit 15, and the concentration value Y of residual chlorine is calculated based on the calibration data stored in the calibration measurement value storage unit 16 and the concentration test value storage unit 19.

Here, assuming that the residual chlorine concentration value Y of the water in the hot spring bathtub 1a is proportional to the minute current flowing through the sensor 12, it can be calculated by the following equation (1).
Y = Ka (X-Sz) / (Sa-Sz) (1)

  The concentration value Y calculated by the chlorine concentration calculation unit 15 is given to the concentration determination unit 17, and it is determined whether or not the concentration value Y is within an appropriate concentration range. If the density value Y falls below the lower limit value, the lower limit detection signal LL is output to the sequence control unit 20, and if the density value Y exceeds the upper limit value, the upper limit detection signal UL is output to the sequence control unit 20.

  The sequence control unit 20 controls to increase the injection amount of the chlorine injection pump 5a when the lower limit detection signal LL is output from the concentration determination unit 17, and this chlorine injection pump when the upper limit detection signal UL is output. Control is performed to reduce the injection amount of 5a.

  When the measurement and control of the water quality of the hot spring bathtub 1a are finished, the measurement and control of the water quality of the pool 1b are then performed in the same procedure. The concentration value Y of residual chlorine in the test water in the pool 1b is calculated using the calibration measurement value Sb and the concentration test value Kb in place of the calibration measurement value Sa and the concentration test value Ka in the equation (1). Is done.

  When a series of water quality monitoring of the hot spring bathtub 1a, the pool 1b, etc. is completed in this way, the next monitoring is performed based on the plan data stored in the operation plan data storage unit 21.

  As described above, the residual chlorine concentration monitoring system of the present embodiment includes the concentration inspection values Ka and Kb of the residual chlorine concentration inspected by the DPD method, and the calibration measurement values Sa, The residual chlorine concentration value Y is calculated from the measured value X periodically measured by the sensor 12 using Sb and the zero point correction value Sz as calibration data. Thereby, the concentration value Y of the residual chlorine of water of a plurality of systems having different water quality such as a hot spring or a pool can be switched and monitored one after another using one sensor 12 for measuring residual chlorine. Therefore, there is an advantage that highly accurate water quality monitoring can be continuously performed with a simplified system without using an expensive measuring device for each measurement target.

  The embodiments described above are only for clarifying the technical contents of the present invention. The present invention is not limited to the above-described embodiments and is not construed in a narrow sense, and various modifications can be made within the scope described in the claims of the present invention. Examples of such modifications include the following.

(A) The residual chlorine concentration inspection method as an evaluation standard is not limited to the DPD method, and an o-tolidine colorimetric method, an iodine titration method, or the like can be used.

(B) For pools and hot springs where the number of users varies depending on the season, day of the week, and time, change the frequency of water quality monitoring by time based on the predicted number of users. By doing so, it becomes possible to maintain more stable water quality.

(C) If the water quality exceeds the control limit as a result of water quality monitoring, the schedule may be changed so that the system is monitored in a short period until the measured value returns to the normal range. . However, when sterilizing chlorine is injected into a large pool, it takes a long time for the chlorine to uniformly diffuse throughout the pool, so the relationship between the sterilizing chlorine injection position and the water intake position for inspection, etc. Considering this, it is necessary to control the chlorine injection pump and set the monitoring time interval.

(D) The sequence control unit 20 controls the chlorine injection pump 5 according to the lower limit detection signal LL and the upper limit detection signal UL output from the concentration determination unit 17, but the residual chlorine output from the chlorine concentration calculation unit 15 The operation time of the chlorine injection pump 5 may be controlled according to the concentration value Y. For example, the residual chlorine concentration value Y may be divided into about 10 stages, and the operation time of the chlorine injection pump (that is, the chlorine injection amount) may be set for each division.

(E) By changing the type of sensor, not only the residual chlorine concentration but also other elements for water quality management may be measured.

(F) The zero point correction value Sz does not use the value measured at the time of acquisition of the calibration data, but uses the measurement value output from the ADC 13 immediately before collecting the sample water every time the residual chlorine concentration is monitored. Also good. Thereby, the error due to the fluctuation of the zero point can be reduced.

  As an application example of the present invention, it can be used not only for water quality management of hot springs and pools but also for monitoring air pollution.

It is a block diagram of the residual chlorine concentration monitoring system which shows the Example of this invention.

Explanation of symbols

11 Solenoid Valve 12 Sensor 13 ADC (Analog / Digital Converter)
DESCRIPTION OF SYMBOLS 14 Calibration data input part 15 Chlorine concentration calculation part 16 Measurement value storage part for calibration 17 Concentration judgment part 18 Inspection data input part 19 Concentration inspection value storage part 20 Sequence control part 21 Operation plan data storage part 22 Touch panel

Claims (6)

Water intake means for switching and collecting water from multiple systems according to a selection signal;
Detection means for outputting an electrical signal corresponding to the concentration of the specific component contained in the water collected by the water intake means;
Conversion means for converting the electrical signal output from the detection means into a digital value and outputting it as a measurement value;
A first storage unit that stores the measurement value output from the conversion unit as a measurement value for calibration for each of the systems when acquiring calibration data for the water of the plurality of systems;
Second storage means for storing, for each system, a concentration test value obtained by inspecting a concentration of a specific component contained in water collected by the water intake means at the time of calibration data acquisition by an inspection method as an evaluation standard; ,
For the water of each system collected by the water intake means at the time of water quality monitoring, the measurement value output from the conversion means is calibrated using the calibration measurement value and the concentration test value corresponding to the system. Density calculating means for calculating the corresponding density value;
Control means for outputting the selection signal for the water intake means and controlling the entire operation sequence based on operation plan data given in advance.
A water quality monitoring system characterized by comprising. The concentration calculating means converts the zero point adjustment value, which is a measurement value output from the conversion means when water is not collected by the water intake means, to Sz, corresponding to the water collected by the water intake means. X is a measurement value output from the means, Sa is a measurement value for calibration of water of the corresponding system stored in the first storage means, and water of the corresponding system stored in the second storage means The water quality monitoring system according to claim 1, wherein the concentration test value is Ka, and the concentration value is calculated using an equation of Ka (X−Sz) / (Sa−Sz). The water quality monitoring system according to claim 1, further comprising a concentration determination unit that performs control for maintaining water quality of a corresponding system according to the concentration value. 3. A concentration determination means is provided for issuing an alarm when the concentration value is outside a predetermined control limit or performing control for maintaining water quality of the corresponding system. Water quality monitoring system. 5. The water quality monitoring system according to claim 3, wherein the specific component is residual chlorine, and the control for maintaining the water quality is an amount of chlorine for sterilization injected into a corresponding system. The water quality monitoring system according to claim 5, wherein the operation plan data is configured by season, day of the week, and time zone.

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